Young Rölf is a character in Zombies in the Snow, a movie directed by Gustav Sebald. Rölf refuses to hide from the zombies behind the oak barriers like the rest of the town folk, instead continuing to build his snowman.
In Lemony Snicket: The Unauthorized Autobiography, a letter written from Sally Sebald to Lemony Snicket contains a picture of the actor who played the young boy. Sally thinks his name might be "Omar", a name that is often confused with "Olaf" in A Series of Unfortunate Events. However, the film contains a message using the Sebald Code for Dr. Montgomery about the Baudelaire children, which means the film must have been recently filmed and the actor must still be a child and thus not Count Olaf.
In the TV adaption, Gustav portrayed Rölf.